Dependency injection without ts metadata

[tobiasdiez]

Esbuild doesn't support 'emitDecoratorMetadata' and doesn't intend to support it in the future: evanw/esbuild#257, evanw/esbuild#509. There is also no real hope that one could write an esbuild plugin that does the job in the near future: evanw/esbuild#111. Our current solution to run typescript on every module is slow and kind of defeats the purpose of esbuild.

Thus, we migrate tsyringe nice concept to automatically recognize the type of the dependency (using the emitted metadata) to explicitly annotating each dependency with @inject('Type'). This is similar to https://github.com/inversify/InversifyJS/blob/master/wiki/classes_as_id.md.

Things that one could still improve in the future:

• Allow types to be passed in instead of strings, e.g. @inject(AuthService)
• Extend the injectSymbol method to automatically register a symbol -> class alias so that we don't have to do this manually in tsyringe.config (there might be problems with circular imports if this approach is used).
• Remove reflect-metadata as soon as Usage without Reflect microsoft/tsyringe#180 is fixed